Welcome, John!
I'm arriving late to the conversation here; scanned through most of it, but I might have missed this one tidbit.
A couple nice things about ordering from Graf's, as opposed to some other powder houses: (1) they'll sell in 5# lots; many other suppliers require a 20-25# purchase. Fine, if you're buying for a club; not so useful, for most of us loners.
(2) They'll "mix-and-match" orders, to make up that 5# minimum, within a like product line (for instance, you can order 2# of 2F; 2# of 3F, and a pound of 4F for priming, etc.). My understanding is, as long as it's the same product, it counts toward the minimum. If you want to try various makes or products, you might call ahead and see if they'll do that for you: the minimum sales requirements for BP are mostly due to the Fed hazmat rules and fees.
I think you'll be happy with a GPR for your first muzzleloader; a pawnshop-find flintlock .50 GPR was my first, and I found it to be surprisingly accurate for a factory-built, price-point, import arm. I'll never sell it; in fact, after some TLC it'll be gifted to one of my three kids, or their spouse.
I believe it was OMM who suggested replacing the lock with the L&R RPL lock; I did, and it really helped solve the flash-fizzle issue. TOW and Muzzleloader Builders' Supply both offer them, online.